Tempestade Tropical FIONA (Atlântico 2010 #AL08)

[Rog]

Do invest 97L, formou-se no Atlântico a Tempestade tropical Fiona.

Aviso n.1:

...TROPICAL STORM FIONA FORMS EAST OF THE LEEWARD ISLANDS...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...14.4N 48.7W
ABOUT 890 MI...1435 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HR
PRESENT MOVEMENT...W OR 270 DEGREES AT 24 MPH...39 KM/HR
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
NONE.

INTERESTS IN THE NORTHERN LEEWARD ISLANDS SHOULD MONITOR THE
PROGRESS OF FIONA. A TROPICAL STORM WATCH MAY BE REQUIRED FOR A
PORTION OF THIS AREA LATER THIS EVENING OR TONIGHT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 PM EDT...2100 UTC...THE CENTER OF TROPICAL STORM FIONA WAS
ESTIMATED NEAR LATITUDE 14.4 NORTH...LONGITUDE 48.7 WEST. FIONA IS
MOVING TOWARD THE WEST NEAR 24 MPH...39 KM/HR. A TURN TOWARD THE
WEST-NORTHWEST IS EXPECTED ON TUESDAY...FOLLOWED BY A TURN TOWARD
THE NORTHWEST AND A DECREASE IN FORWARD SPEED ON WEDNESDAY. ON
THIS TRACK...FIONA COULD BE NEAR OR JUST TO THE NORTHEAST OF THE
NORTHERN LEEWARD ISLANDS BY EARLY WEDNESDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES...220 KM
TO THE NORTHEAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB...29.74 INCHES.

 

[Vince]

Um pouco discutível a nomeação deste ciclone para já. Estruturalmente está bastante pobre, um avião da NOAA que andou em toda a região a lançar sondas, numa delas foi registado vento de 35kt que sustentam esta classificação, ok, está certo, mas não me recordo de alguma vez ter visto um sistema com uma estrutura destas a ser classificado.

EARLIER TODAY...ABOUT 30 DROPSONDES WERE RELEASED DURING A G-V
RESEARCH MISSION BEING CONDUCTED BY THE NATIONAL CENTER FOR
ATMOSPHERIC RESEARCH NEAR THE AREA OF LOW PRESSURE LOCATED ABOUT
800 MILES EAST OF THE LESSER ANTILLES. ONE OF THE DROPSONDES
MEASURED A SURFACE WIND OF 35 KT APPROXIMATELY 120 N MI TO THE
NORTHEAST OF THE ESTIMATED CENTER. THIS MEASUREMENT AGREES WITH AN
ASCAT PASS FROM 1208 UTC...WHICH SHOWED A SWATH OF 30-35 KT WINDS
IN THAT SAME AREA. CONVECTION HAS BEEN A LITTLE THIN FOR MOST OF
THE DAY...BUT BANDING FEATURES HAVE RECENTLY BECOME MORE PROMINENT
MAINLY OVER THE WESTERN SEMICIRCLE. GIVEN THE INCREASE IN
CONVECTION AND SINCE TROPICAL STORM FORCE WINDS ARE ALREADY
OCCURRING...THE SYSTEM IS BEING DIRECTLY UPGRADED TO TROPICAL STORM
FIONA.

SINCE FIONA STILL LACKS SOME ORGANIZATION AND THE WIND FIELD IS
SOMEWHAT LARGE...THE CYCLONE WILL LIKELY HAVE A DIFFICULT TIME
INTENSIFYING OVER THE NEXT DAY OR SO. I DO NOT BELIEVE THIS
STRUCTURE IS HANDLED WELL BY THE STATISTICAL INTENSITY
GUIDANCE...WHICH INTENSIFY FIONA TO A HURRICANE IN 36 TO 48
HOURS...SO I AM INCLINED TO LEAN CLOSER TO THE DYNAMICAL GFDL AND
HWRF AT THIS POINT. IN FACT...THE GFS DISSIPATES THE CYCLONE WITHIN
2 TO 3 DAYS. THE OFFICIAL FORECAST THEREFORE SHOWS MINIMAL
STRENGTHENING OVER THE NEXT 1 TO 2 DAYS AND THEN LEVELS OUT THE
INTENSITY FOR DAYS 3 THROUGH 5...WHEN IT APPEARS THAT INCREASING
VERTICAL SHEAR COULD BECOME A LIMITING FACTOR.

THE SURFACE CENTER HAS BEEN A LITTLE DIFFICULT TO LOCATE...AND THE
INITIAL MOTION IS AN UNCERTAIN 270/21. TRACK MODEL GUIDANCE IS IN
GOOD AGREEMENT FOR THE NEXT 48 HOURS AND SHOWS FIONA TURNING TOWARD
THE NORTHWEST...GENERALLY FOLLOWING EARL AROUND THE WESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE. AFTER THAT...THE
GFDL...HWRF...AND GFS KEEP FIONA AS A WEAK SYSTEM AND SHOW IT
CONTINUING TO THE NORTH IN THE LOW-LEVEL FLOW BEHIND EARL. THE
ECMWF...ON THE OTHER HAND...SHOWS A STRONGER FIONA AND SUGGESTS
THAT THE SUBTROPICAL RIDGE COULD BUILD BACK TO THE WEST BEFORE THE
CYCLONE CAN RECURVE. THE OFFICIAL FORECAST IS VERY CLOSE TO THE
MODEL CONSENSUS TVCN FOR THE FIRST 48 HOURS BUT THEN LIES A LITTLE
NORTH OF THE CONSENSUS IN FAVOR OF THE TRACKS OF THE WEAKER GFDL
AND HWRF.

 

[analuu]

ha alguma probabilidade de passar por punta cana ate sabado e dai em diante?

 

[Vince]

ha alguma probabilidade de passar por punta cana ate sabado e dai em diante?

Alguma probabilidade há sempre nestas coisas, mas Fiona passará a nordeste da Republica Dominicana antes disso, ainda esta quinta-feira e em princípio já razoavelmente afastada. Para a próxima semana acompanha a nova perturbação, a 98L. Nesta altura do ano é sempre assim, umas atrás das outras para vigiar :-)

 

[Vince]

Tempestade Tropical FIONA tem gerado mais convecção mas permanece bastante desorganizada em termos de circulação.

Devido à proximidade do poderoso Furacão EARL, o outflow deste certamente provocará shear que impedirá grandes intensificações da FIONA, tal como é provável que a FIONA apanhe água menos quente devido ao upwelling provocado pelo mesmo Furacão. De qualquer forma o NHC avisa que é tudo bastante incerto pois é uma sinóptica complexa.

 

[Vince]

FIONA mantém-se como Tempestade Tropical moderada segundo dados recolhidos por avião. O aspecto não está grande coisa, com o centro a ficar exposto a norte. Viver na sombra do gigante "Earl" nunca lhe deu grandes hipóteses de se desenvolver mais.